Both Type 1 and Type 2 diabetes greatly increase the risk of dying from heart disease and are leading causes of blindness, leg amputation and kidney failure. There is now conclusive evidence that these long-term complications of diabetes can be prevented by keeping blood glucose levels as near to normal as possible. However, achieving this with conventional insulin injections results in a three-fold increase in the number of incapacitating attacks due to low glucose levels. Moreover, sufficiently good control can often only be attained through considerable ongoing effort from the individual and intensive input from health services. In the rapidly-moving field of gene therapy, new ideas for alternative solutions to insulin injections are continually being generated and examined.